The U.S. Soccer Federation announced the format for the 2023-24 U.S. Open Cup on Friday, confirming that only eight of a possible 26 MLS teams will have their first teams participate.

Atlanta United FC, FC Dallas, Houston Dynamo FC, LAFC, Real Salt Lake, San Jose Earthquakes, Seattle Sounders FC and Sporting Kansas City are the MLS teams that will play with their first teams.

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Eight of the nine MLS teams that qualified for this year's Concacaf Champions Cup will not take part in the U.S. Open Cup in any capacity, with the exception of the defending Open Cup champion Houston Dynamo.

It means Lionel Messi and Inter Miami, who reached the final last season, will not participate in this year's competition.

The MLS first teams participating consist of the top seven ranked U.S.-based teams -- based on the 2023 MLS Supporters' Shield standings -- not involved in the Concacaf Champions Cup.

Of the 10 remaining MLS clubs, nine will have their MLS Next Pro teams participate from the first round: Austin FC II, Chicago Fire II, Colorado Rapids 2, Crown Legacy (affiliated with Charlotte FC), Minnesota United FC2, LA Galaxy II, New York City FC II, New York Red Bulls II and Portland Timbers 2.

The lone team not participating in the Concacaf Champions Cup or the Open Cup in any capacity is D.C. United, which does not have an MLS Next Pro team.

All told, eight Division I teams, 24 Division II teams, 32 Division III teams and 32 open division teams will compete for the 2024 title, with $300,000 going to the winner.

The U.S. Open Cup crowned its first winner back in 1914, making it one of the oldest soccer competitions in the U.S., and allows professional and amateur teams to participate together in a single elimination tournament.

This creates possible giant-killing scenarios as lower-tier teams go up against their professional counterparts.

In a change to the tournament's format, the upcoming first round will mark the first time since 2008 that all 32 matchups will pit amateur against professional teams.

The USSF also announced new commercial partners, including Marriott, Michelob Ultra, New York Life and Nike.

This allowed U.S. Soccer to prioritize enhanced financial incentives for participating teams, including significantly increased travel reimbursement. The federation has also committed to increased promotion of the tournament.

"First and foremost, I want to extend my sincere gratitude to all our members for their invaluable input over the past couple of months -- sharing with us of the reasons the U.S. Open Cup is so great, and what we can do to make it even better," U.S. Soccer CEO JT Batson said. "After extensive discussions, we have put together a competitive format specific to the 2024 Lamar Hunt U.S. Open Cup, promising exciting matchups from the First Round and through the entire tournament.

"U.S. Soccer values the tradition and importance of the U.S. Open Cup, and we will continue to have conversations with all our members to explore avenues for enhancing future editions of the tournament and how we all work together to grow soccer in every community in the country."

Nelson Rodriguez, MLS' EVP of sporting product and competition, said there have also been economic changes. What he called "onerous hosting fees" have been eliminated, with hosts also allowed to keep more ticket revenue.

United Soccer League president Paul McDonough added, "The USL has supported the Lamar Hunt U.S. Open Cup for nearly 30 years, and we are proud to be part of it again in 2024. We applaud all the USL clubs who have decided to participate in this year's U.S. Open Cup, despite being handed the option to decline. We appreciate and share the fans' passion for our country's most historic and authentic competition, and we look forward to watching the drama unfold over the course of the tournament."

Although the tournament has long held appeal to longtime soccer fans in the U.S., it has struggled to attract investment and a broader audience, and the future of the tournament has been in doubt ever since MLS announced in December that, because of fixture congestion, its first teams wouldn't participate in the competition and that teams from MLS Next Pro would take their place.

MLS commissioner Don Garber has often voiced dissatisfaction with the tournament, and he continued his critiques in a February interview with ESPN.

"Everybody in the soccer business [needs] to rethink how competitions have been organized to ensure that we can continue to evolve and manage what is the single-biggest issue for all professional soccer, and that's the management of our schedule," he said.

Although it's true that MLS' schedule has become more crowded in recent years, some of that is the league's own doing with its creation of the Leagues Cup in collaboration with Liga MX.

MLS' stance was at odds with the USSF's professional league standards, which are designed to set minimum standards for items such as the finances of owners, stadium capacity and market size. In this case the standards state that teams from a top-flight outdoor league "must participate in all representative U.S. Soccer and CONCACAF competitions for which they are eligible."

Five days after MLS' statement, the USSF announced, "Major League Soccer has requested to allow MLS Next Pro teams to represent MLS in the 2024 Lamar Hunt U.S. Open Cup. After thoughtful consideration, we have informed MLS that the U.S. Soccer staff recommendation, which was adopted by the Pro League Taskforce, is that the request be denied."

MLS' desire to have only its reserve teams participate also caused issues at the confederation level.

The winner of the Open Cup earns a spot in the Concacaf Champions Cup, and a source with knowledge of Concacaf's thinking indicated that had the Open Cup become a competition only for teams in the second tier and below, this would have raised protests from other countries in Concacaf.

The source indicated that these concerns, although falling short of a demand, were communicated to the USSF by Concacaf.

But MLS continued to work against having all of its teams participating. A seven-person USSF subcommittee of its board of directors was formed in December 2022 after the issue became public.

Last month, the subcommittee decided that the 2023-24 tournament would go ahead with a hybrid format that included some MLS first teams.

"I don't know that anything changed after our request was denied as much as it was just a continuance of discussions," Rodriguez said.

That approach didn't go over well with the USL, which runs leagues that comprise some of the lower tiers in the U.S. soccer system.

At one point, some teams in the second-tier USL Championship threatened not to participate, but eventually all of the organization's 47 teams agreed to take part.

That the USSF was appearing to waive its own requirements for top-flight teams to participate still caused upset within the USL ranks, though.

USL's McDonough said, "I'm disappointed that U.S. Soccer hasn't handled the whole situation in a stronger or better fashion."

The format announced on Friday is only for 2024. Rodriguez indicated that the USSF is forming a "working group" that will work with stakeholders to determine what format will be used for 2025.